How to Paint your Z

Well, a few people asked, so here is the long version of what I did to
paint my 260-Z. I did this job on weekends and holidays, a few hours
at a time. I began stripping the car back in June, and put the last
clear coat on in early November. I still have to reassemble the car,
plus acquire a few more gaskets and seals from Motorsports. I broke
this down into a series of major topics, to show how I planned and
thought about the job.

Research:

I got interested painting by reading a thread on paint on the z-car
list shortly after I joined. Besides some of the hints included in
those posts, I obtained a couple of books:

"How to Paint Your Car"

and

I probably leafed through others as well.

I also sought the advice of a couple of body shop supply houses, and
got a lot of useful information from Stone Auto Body Supply in
Watertown; kudos to them for taking the time to listen to my needs and
help me choose materials and supplies.

A Place to Paint:

The first order of business was to give some thought to how I could do
this and still get a decent job. I decided to use "my side" of the
garage, since the Z was sitting there anyway. It's a two car garage,
under the house at the basement level. The fireplace chimney is
between the two stalls on the outside, so the garage is extra-wide.
Also the house gets wider toward the "rear" of the garage (the end
away from the doors); about 6 feet from the back wall the garage
widens a few feet on each side. The whole space is finished and
insulated. Lolly columns run down the middle between the stalls to
support the room above.

I wanted to make it as dust-free as possible, and provide ventilation
and compressed air convenient. I also needed it to be easy to set up
and break down, since I didn't want to live with big structural
changes, like studded walls. My workbench and tool boxes live at the
front of that side, so I would need things back as they were in order
to continue on with car and household projects after the painting was
done.

Dust-Free:

Following the suggestions in the books, I used 6 mil plastic, bought
from Home Depot. The plastic was stapled to 1x2 strapping, which I
installed in advance on the ceiling around the perimeter of the spray
booth area with drywall screws. I stapled the plastic up on spray
day, taping it to the floor with duct tape and cutting it for the fans
and air outlets as needed. I used two large 10x25 rolls, and started
from the garage door jamb on each side. The two sheets met at the far
end of the garage with about 8" overlap; I left this gap as a door,
and taped it up just before painting. I believe this enclosed an area
roughly 12'x18'.

As an afterthought, I had some 1 mil plastic left to me by a house
painter some years back, and I used this on the ceiling of the garage,
fastening it to the already in-place strapping.

With a mechanical staple gun and 9/16 staples, the installation is
pretty fast.

Ventilation:

I constructed two frames to support standard "box fans". Picture two
inverted T's, with the cross-bars parallel, held together by
horizontal members. These made out of 2x3. I built the T's and cut
the horizontals, and stored the pieces leaning against convenient
walls until "spray day" Then I fastened them together on "spray day"
with drywall screws. I placed one of these one each side, facing each
other, right at the "back" of my spraybooth (the front being the
garage door). On one side the structure sits in the alcove where the
garage widens, and on the other its sitting next to the last lolly
column before the back wall. The plastic got stapled to these (they
helped define the "corners" at the rear wall of the booth. I cut a
hole in the plastic for each fan, and taped the plastic to the fan
housing for a tight seal

The fans were 10 inch, 10 dollar specials from BJ's (like Price Club).
I would recommend bigger fans, they moved air pretty slowly. The fans
blow into the spray area, and the backside of each fan is covered by a
standard 20x20 paper furnace filter; any gaps on the intake side were
sealed with brown cardboard and masking and/or duct tape. The fans
and filters were mounted in the wooded frames mentioned above.

The garage door I left open while spraying, hoping that the fans
forcing clean air in the rear would exhaust the fumes to the front.
WHile spraying, I frequently hosed the driveway to minimize dust blown
in by the wind.

Another aspect of this design is that the (flammable!) paint fumes are
not drawn through the electric fan; only clean air is handled by the
fan.

Compressed Air Supply:

I have a Sears compressor, they rate at a ridiculous 4HP. It could
only be 2 1/2 or so based on the amperage draw. I've already broken
this once, they were unable to repair it and gave a replacement under
warranty. Buy something else, unless you like the idea of $300
disposable tools!

I built an air delivery system for the bay using 1" copper pipe for a
main air line and 3/4" drops. Basically, the main line runs from the
back wall straight down the middle, then runs over the door on "my"
side. I used four drops in various places around the garage - one on
the back wall near my workbench, one between the stalls on the lolly
column closest to the back wall, and one on each side of the garage
door opening. The main pipe slopes slightly down for the whole run,
and the drops all go up, then make a u-turn to come down -- standard
approach to help keep moisture from getting to the spray gun. Most of
the drops have a moisture trap.

Following advice from either this or the hotrod list, I used a ball
valve on each drop and a ball valve to isolate the system from the
compressor. All the stuff for this I bought at Home Depot. This part
I put up well in advance.

Tools and other:

I bought a DevilBiss spraygun, owing mostly to the desire for being
able to keep and repair it over a long period of time. I believe the
Sharpe and Binks are two other well-known brands used by pros. If
you're doing a one-shot never-again job, a cheaper gun might be ok.
Since I had no clue as to how to assess a spray gun, I bought a
name-brand. All I can tell you is that the DB gun worked superbly and
was easy to adjust, use and clean. I thought about buying a cheap
jamb gun for some of the work, but never got around to it. I used a
small regulator right on the gun to control the pressure at the gun; I
set the main regulator for the compressor to 90-100 psi.

I also collected other miscellaneous stuff during this period --
rubber gloves, respirator, tack cloths, scotch-brites, tons of
sandpaper, some "Rust Mort" stuff for a couple of hard to reach areas
(e.g. inside the driver's door). In short, I collected everything in
my inventory that I though I might need to derust, prep, and paint the
car.

Auto Preparation

Well, yes, there is a car somewhere in this story, and here's its turn
in the spotlight. It's a '74 260-Z I acquired in 1977; I believe it
was a turn-in on a lease. The car lived most of its life in southern
California, and was garaged much of the time I had it, so there is
virtually *no* serious rust anywhere.

At the time I acquired it, the original metallic silver was starting
to go, and about 3 years later I had it repainted. The guy said he
was using Dupont Imron, but this paint job also chalked and
deteriorated within about 3 years. The body shop supply house
suggested it was not Imron, else it would have lasted better and would
have been harder to strip.

Exterior Stripping

I removed the bumpers, lights, mirror. I looked at the old windshield
and hatch mouldings, and decided they would have to go as well. To
help clean under them, I forced thick white cord under the edge of
these mouldings; this lifted the rubber slightly and let me clean and
paint slightly under where the new moulding will set, and should help
prevent any breaks in the protection of the metal underneath at the
moulding line. A better way to do this would have been to remove the
windshield and hatch glass; I was just running out of decent weather
at this point.

I removed most other weatherstrips as well, after 20 years, they had
pretty much lived their useful lives.

Paint Stripping

General advice is to remove paint in the gentlest way consistent with
the condition of the car. Mine was just chalked, and had only one
repaired area that I knew of, so I chose a chemical stripper. The
supply house sold me Kleen-Strip's "Aircraft Stripper", but I'm sure
there are other brands. It worked great, one application lifted both
coats of paint and often the primer right off the bare metal. Not
something you'd want to spill on anything you care about. Interesting
stuff to put in a styrofoam cup (the cup lasted about 10 seconds).

In the first stripping pass, I did the whole car up to within an inch
or so of the "edges" of things. Then I did a second pass after
carefully taping up "edges" to keep the stripper from taking off paint
I wanted to meld the new coat into. Basically I wanted to do the
exterior body panels, but I did not strip door jambs or wheel arches,
or the interior of the car (this is one of those 100's of decisions I
found myself making during this restoration -- how far to go with any
particular step; in this case I wanted to finish exterior paint before
New England's winter made working in the garage uncomfortable, so I
left alone areas that were in good shape or that didn't show). I can
go back and work these undone areas later without impacting the
exterior paint job.

The driver's door had been dinged and bondo'd in a couple of places,
other than that, and the little holes all down both sides for the side
mouldings, the car was clean and straight. I noticed I have one
fiberglass and one steel head light bucket, which probably meant some
damage was done to the front at some time. The hood showed a lot of
surface rust, and both the hood and top had a few tiny rust "pits"
beginning to develop.

I filled all the body damage with solder, using Eastwood as a source
for the stuff. It was very easy for the holes, and required only a
propane torch. The ding on the driver's door was bigger and harder to
fill; the job I did there is not perfect, but it was good enough for
now. This doorskin has enough rust on it's bottom lip to that I will
want to replace it eventually anyway. I believe the "ding" in that
side distorted the doorskin enough so that the rubber-and-chrome strip
along the top of the doorskin didn't even touch the window glass; as a
result there was a lot of rusting inside the door.

I sanded the whole car with 80 grit then with 200 grit, and treated
all the surfaces with Oxysolv. This seems to be a weak phosphoric
acid solution that etches off the last of the rust and leaves a
protective zinc phosphate coating behind. It removed any non-visible
rust that might have developed as the bare car sat exposed for several
months in my garage.

Interior stripping

I removed the interior panels, seats, and carpets. Partly to minimize
paint dust clean up, and partly check panel backsides and floors for
rust and such.

Some rust in the spare tire well and on the passenger floorboard, but
not to the point of requiring metal surgury. I cleaned it and
neutralized it, then primed/painted with Rustoleum. Again, this was a
non-appearance area, where I just wanted to protect the metal from any
further water damage, and maybe deal with it differently on another
day.

Paint Selection

I chose acrylic urethane over acrylic enamal. The acrylic enamal
sprays in one step, but has limited durability. The acrylic urethane
requires basecoat and clearcoat, but supposedly lasts much longer. An
interesting note in all this was that I found out I had been cheated
by the body shop that painted the car 12 years ago. They claimed to
use "Imron"; the local shop said what I had came off far too easily to
be Imron (pretty much the first application of stripper removed both
coats of paint). It was probably painted with an acrylic enamal; it
definitely was not basecoat/clearcoat. And the prep work must have
been poor, the second job in some areas could be peeled right off the
first.

Imron, by the way, is "polyurethane" enamal; it is supposedly very
durable, but difficult to apply well. I was told that it's seldom
used on autos, but is more common on trucks.

The alleged Imron was a dark silver, for this job I went back to the
factory color code "Sterling Silver".

My local emporium carries PPG stuff, so I used it throughout.

I should remind everyone here that these paints contain pretty foul
stuff (just about every nasty hydrocarbon solvent, plus cyanide
compounds), and need to be sprayed with a respirator. The safest way
is with a forced fresh air mask; I used a regular respirator and lots
of ventilation.

I'd also point out here that you should carefully read the spec sheets
on the paints you want to use; they are meant for pros and often have
a lot of restrictions that are ok in a body shop but could be killers
for the weekend warrior. Things like "recoat within the hour, or wait
24 hours before recoating" (DAU 82). Or the DP - recoat within a
week, else you have to scuff, add another coat of DP, and then add the
topcoats. In other words, once you start spraying, the materials
themselves will drive the schedule/sequence to a great extent.

Masking

I used brown paper and tape. I unbolted the hatch from the hinges,
and bolted two 6" pieces of metal between the hatch and the hinges.
This held the hatch up and open for painting. I had some rust and
pitting in the hatch jamb area between the hinges, and wanted to be
able to thoroughly clean and paint it. I masked both sides of the
hatch, taping on where the gasket would go as a line. I masked both
door openings, also taping where the seal usually sits. I had not
stripped these jamb areas, but I scuffed and sanded them so the new
layers of paint would take. I did all this the weekend prior to
painting the car, except for the wheels. On paint day, I rolled the
car out, wahed and degreased it; and rolled it back in and masked the
wheels before tacking and painting.

Priming

I went over the car with a wax/grease remover, and tacked it off
before spraying. This is a routine step to help keep the job clean,
and its critical when working in a relatively dirty space like a
garage. I tacked between almost every coat of paint.

I used DP-50 epoxy primer (50 is the code for gray). It was very easy
to spray. Two quarts of primer and two quarts of activator make a
gallon of paint; I was able to put 2 complete coats on the car with
this, covering the exterior, the door jambs, the hatch jamb, and the
cross member under the radiator. DP can be topcoated after fairly
short drying time, and must be topcoated within a week, or you get to
scuff it, put on another coat of DP, and then put finish coats over
that. Getting the DP on was as far as I got on day one.

To fill the minor scratches from the body file or places that had been
severely sanded, I used NCT-250 primer-surfacer. One quart of this
stuff did all the areas that needed minor filling/surfacing. This
stuff needed a couple hours drying time before sanding.

I wet sanded the primer with 400-500 grit paper, per this instructions
with the paint. Once it was all smooth and cleaned off I went
directly to color coats.

Painting

I had chosen PPG DBU basecoat, in a metallic silver color. It sprays
*a lot* differently than DP, and I created terrible runs on the first
spray gun pass, with way too much paint coming out. I found I had to
cut the paint volume way back and use a pretty fast steady stroke to
get decent looking passes. After two light coats, I called it a
night.

Sunday morning I sanded the grossest color flaws off, and cleaned up
and then went on with color coats after the air temperature reached
the 65 or so maximum it was likely to achieve. I was spraying it
pretty light, and probably put on 3-4 complete coats before acheiving
complete coverage of the purple colored primer surfacer. By this time
it was around 5pm, and the color needed around an hour's drying time,
so we went out to dinner. Back by around 7pm, I shot four clear coats
over the car. This was much easier to spray than the metallic color.
Unfortunately stormy weather was blowing through the area that
evening, so contending with dust was worse at this time than it had
been for the whole rest of the job (Murphy's law, I guess) The paint
here was PPG DAU 82.

The car has been drying since then, the spec sheet said to give it 7
days before rubbing it out, so I may work on buffing it this weekend.

Altogether I had about 20 hours of painting time in the job.

Mistakes/problems:

Air hoses - I bought cheap ($10) plastic ones from BJ's (like Price
Club), and they are a pain when painting, because when you twist them
they want to form loops and when you drag them they want to unloop by
jumping up into your paint job. Shell out the extra for nice rubber
hoses that behave better.

Light - I was originally hoping to do this earlier in the summer and
just work when it's light, so I bagged plans to put extensive lighting
over the work area, even though books and the painters on this list
recommended it. I noticed on the day I finished that the local
discount store had those sit-on-the-ground halogen work-lights for
$10. Four or so of those jerry-rigged above/around the car would have
been pretty cheap, and made the late afternoon/evening painting
easier.

Ventilation/dust - I wanted, and discovered I could have used, bigger
fans, like a 14" box fan or so. But by the time I went looking the
were sold out locally; I ended up using some little fans we'd bought
earlier in the summer for use around the house.

Not practicing - I have a parts car, and could have stripped and
prepped a panel from it and used that to experiment on. That would
have improved the quality of the job, because I would have found some
of the flaws in technique that way. Working against this is the
nature of the materials -- the paints are expensive and cannot be
saved long once mixed -- whether you do arrange practice or not may
depend on how perfect a result you want on the final job versus how
much time/money you're willing to invest. My job came out good enough
without it, would have been a little better/quicker with it.

Accounting:

I saved all the receipts from the restoration, and the stripping and
painting phase seems to break down approximately as follows:

Paint:

$450 (DP-50, NCP-250, DBU color, and DAU-82 clear)
1 quart of NCP-250; 2 quarts of everything else.
2 quarts makes a gallon or more, since most of them
mix 1:1 with activator.

Strip/Prep

$150 (sandpaper, scrapers, brushes, gloves, etc, etc)

Air supply

$300 compressor
$150 spray gun
$300 piping/fittings/moisture traps

Tools

$300 misc tools/supplies (body solder, etc)

Summary:

While the job definitely has a few flaws, I'm totally thrilled with
it. It has a great "wet-look" silver metallic appearance, and this
without yet having done any buffing. And the acrylic urethane topcoat
looks pretty durable. Also it's repairable, by me or any body shop,
should something unfortunate happen.

As with all things in life, there are a lot of trade offs here. For
me, the desire to learn and do this myself overcame any concern about
concours quality in the final result. In terms of the money spent, I
could probably have spent less, but job and family demand much of my
time, so I sometimes traded $$$$ for time. For example, I did not
shop around at all for the the paint; I established a good working
relationship with one supply shop and went there for everything. I
think there are better deals to be had on air compressors than Sears,
(to say the least!).

I enjoy manual work as a hobby/stress relief/break from my job, which
is focused on things computer and things management. Much of the
enjoyment of the job for me is in the doing, and the learning to do.
I accepted that no way would I match the result of a master auto
painter with years of experience and a proper clean environment; that
just wasn't my goal.

If you're thinking of doing your own paint, I'd advise making sure
that you settle on your own expectations and goals before proceeding;
plan the job as carefully as your environment allows; and then do it
and have fun!

Walter
izc#112

On Mon, 14 Nov 1994, Walter Meares wrote:

>
> > Question though: If you were going to all of the trouble of stripping

> > the car, why didn't you buy a blocking primer such as PPG's K36 and block

> > sand the whole car before painting it? The epoxy primer is good stuff,

> > but I don't necessarily think that it is meant to be directly sprayed

> > upon.

>

> Bearing in mind my answer comes from a novice perspective, and as I recall

> you have access to some professional help...

>

> I'm not familiar with K36, I gather it's a primer-surfacer, and that the goa

l
> of using/sanding it is to have a smoother/flatter body finish? I used the

> NCP-250 to get this effect where I needed it; I didn't find any advice or

> books that indicated primer-surfacing the entire car as a necessary step when

> the body was in good shape already. But if you've advice/experience that

> suggests otherwise, I'd appreciate hearing it!

The NCP-250 is reddish if I remember correctly...it is generally used in
the same manner as the K36, but is much more expensive. Reason being (I
think) is that the NCP is made for cars that already have paint on them,
and for some reason it is more compatible with spot priming...but then
again, I'm no pro either :-)

>

> PPG has such a dizzying array of products, I'd guess that there are many

> combinations that will deliver a super paint job. What did you use on your

> Z to get the result you wanted?

>

I basically did the same thing that you did, stripped with Aircraft
stripper, sanded down all body panels with a DA with 80 grit paper, then
metal prepped using PPG's metal prep. From there, I used the black epoxy
primer (since the car was going to be either black or white, I wanted to
get an idea of what it would like black :-), and *THEN* the body work
started.

My car, unlike yours was not void of any real body work. I had rust
problems in the lower fenders, some in the rear quarters, so all of that
had to be either sandblasted, or cut out with a plasma cutter. I took my
whole car apart, including windows and you'd be surprised at how many
window leaks you can attribute to a rusting window support frame!

After removing all of the bad metal, I welded in patch panels, including
the sidelights that came standard on American Z's. I always thought they
looked tacky and added on, so I just welded them up. Over each of the
weld I used a type putty filler to cover them which we just called "metal
to metal."

Then came the "b" word. Bondo. I was at first aghast at anyone who does
really good quality body work would use bondo, but I've learned since
then that bondo if used correctly is really a great tool. My car had 23
years of knicks, dings, fender benders, just like all other Z's, but it
also had the added benefit of a tree falling on it!

After sanding down the bondo with 36 then 80 grit dry paper, I went to
the next step which is the K36 primer (called PRIMA by PPG) and laid on a
*very* thick coat and started block sanding. The whole car was block
sanded and reprimed probably 10 times. I was very anal about the whole
thing. Like I said before, this was to be show quality. For any low
spots I found I used what we refer to as "glaze" which is just a finer
quality bondo to fill it in.

Finally, the car was done with all of the block sanding...what a pain in
the ass :-) And, the car had to be sealed. We sealed the primer with a
mixture of half k36 and half Concept Clearcoat. Once sealed, the car was
sanded again with 600 grit and was ready to spray base coat.

I used DBC basecoat and the newest PPG Concept Clear coat. We used a
Devilbiss gravity fed gun, and it came out quite nice. But like I said,
I didn't want your average finish, so I sanded the entire car with 1000
grit microfine paper, then 2000 grit to get rid of any dirt, runs and
"orange peel" in the paint.

After the colorsanding, I buffed out the paint using a rotary buffer and
3M's liquid compound. Several steps of Maguire's later, and the car was
finally buffed out. That's where I am as it stands today. The car was
painted in pieces, some of which have yet to make it back on the car, but
overall I'm quite pleased with the results. Even if I do say so myself
:-)

-Scott E. Stevenson

From: spindel@anchor.apl.washington.edu (Bob Spindel)

Subject: More on Painting

Please allow me to add my 2 cents to Walter's excellent posting about
car painting. (Walter, please don't take this the wrong way. You did
a fabulous job and have a wonderful setup. My purpose is to just tell
folks what my experience has been with a somewhat simpler approach.)

I've done 4 cars, two in lacquer and two in basecoat/clearcoat, both
in my driveway, outdoors, with no special 'booth' or 'dust-filtering.'
I've also used an inexpensive $40 gun made by Mark Air, and a Sears
compressor. The gun was recommended to me by fellows who get 99 out
of 100 points on their concours entries. They said it's as good as a
Binks, and I believe them. It worked great for me.

I think the real secret for the do it youselfer is a paint system that
dries fast, and I mean fast, and then allows wet sanding and rubbing
out. Fast drying will prevent dust and bugs, wet sanding (with 1200
or 15oo grit) and rubbing (with PPG or Dupont compounds) will
eliminate any that manage to get in the paint in spite of the fast
drying. Professionals can't afford to spend the time sanding and
rubbing, so they use dust-free booths and heat lamps. But a home
hobbyist can spend a few extra hours on the job. That's what hobbies
are for, right? And remember, most of those concours finishes are
patiently wet sanded and lovingly rubbed out.

Lacquer dries extremely fast, maybe 30 seconds. It's practically dry
when it hits the car. And if there is still a dust speck or two, wet
sanding takes it right out. You can get a really fine finish
outdoors, with no special equipment. Lacquer is also easy to repair.
If it drips or runs, it's dry in a few minutes and you can sand it
smooth and repaint. Lacquer isn't quite as durable as a
basecoat/clearcoat, but it looks just as good if not better. Lacquer
is still the medium of choice for a real classic show car finish.

There are some basecoats/clearcoats that also dry fast. The DBU
basecoat that Walter used dries almost as fast as lacquer, and there
are catalysts for the clearcoat (PPG makes one called Supercharger)
that take them out of dust in a minute or two. Not much dust can
settle in that brief a time, and even if some does, the wet sanding
takes it right out. It's hard to beat for ease of application,
convenience, and a really beautiful finished product. Also, if you
manage to get it all on and dry with no dust specks, it just might be
good enough not to warrant sanding and rubbing. It sounds like
Walter's came out that well. Congrats to him. It ain't easy.

I have also found that a simple water vapor filter attached right to
the gun (about $5) takes out any vapor. I usually use two or three
per paint job. One for the primer and sealer, one for the color coat
and another for the clearcoat.

The beauty of the wet sanding/rubbing process is that you can make a
few errors along the way, even get a bug or two in the finish, and
it'll all come out in the end. How can you beat that?